A guide to personal identification numbers (PINs)

When you use a card at an ATM or to make a payment, you’re often asked for your card’s personal identification number (PIN). But what exactly is a PIN used for? And how does it work?

Read on to learn all about PINs.

Key takeaways

  • PINs are numerical passcodes used for authentication.

  • For payment methods, PINs are used to authenticate in-person transactions like purchases and ATM withdrawals.

  • It’s important for your PINs to be unique and memorable, and there are some best practices worth keeping in mind to help prevent your PINs—and cards—from being compromised.

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What is a PIN?

A PIN is a numerical passcode used for authentication.

PIN uses

When it comes to payment methods like debit cards, credit cards, prepaid cards and electronic benefits transfer cards, PINs are typically used to authenticate in-person transactions and help prevent unauthorized use of the card.

But PINs aren’t just associated with financial transactions, of course. PINs are also used for things like cellphones, tablets and security systems.

How does a PIN work?

PINs provide a layer of protection as a form of fraud prevention.

For financial transactions, the user has to provide the correct PIN when prompted in order to help ensure the transaction is authorized. When the correct PIN is provided, it essentially tells the financial institution that issued the payment method to allow the transaction.

How to create a secure PIN

Whenever creating a secure PIN, it’s important for the passcode to be unique and memorable. Thankfully, a four-digit PIN—like those that debit and credit cards use—allows for around 10,000 different options. But even with all those options, it’s still possible for a PIN to be compromised by fraudsters.

That’s why it’s important to:

  • Avoid repeating digits, like 1111.

  • Avoid consecutive digits, like 1234.

  • Avoid recycling PINs. If you have multiple debit cards, for example, use a different PIN for each one.

  • Avoid using personal details like your birthday or street address.

It’s also a good idea to regularly change your PIN to help prevent unauthorized use.


When you get a new card it will generally come with a preassigned PIN that was randomly generated by the card issuer. It’ll typically appear on the paperwork that accompanies the card. You can also create your own PIN by signing in to your account on the issuer’s website or mobile app, by calling the issuer or by visiting it in person.

You don’t necessarily have to activate a debit card’s PIN. But you might need to use the PIN in order to activate the debit card itself. You can usually do this online through the issuer’s website or app, or by calling the issuer.

If your debit card is lost or stolen, it’s important to contact the card issuer immediately—no matter whether the card’s PIN itself was compromised. The issuer can investigate the potentially fraudulent use of the card as well as replace it with one that has a new card number. Then it’s important to create a PIN that’s different from that of the old card.

No, CVV numbers and PINs aren’t the same thing. A CVV—short for card verification value and also referred to as a card security code (CSC), card verification code (CVC), card validation code 2 (CVC2) or card identification number (CID)—is a three-digit number on the back of the card or a four-digit number on the front of the card. Like a PIN, a CVV is used to help prevent fraud. But a CVV is used for transactions done online or over the phone, while a PIN is used for in-person transactions.

PINs in a nutshell

A PIN is a numerical passcode used for authentication and provides a layer of protection as a form of fraud prevention.

For financial transactions, providing the correct PIN helps ensure the transaction is authorized. The PIN essentially tells the financial institution that issued the payment method to allow the transaction.

Another way you can help protect yourself and prevent fraud is to regularly monitor your credit. Get free copies of your credit reports by visiting AnnualCreditReport.com. Or consider CreditWise from Capital One. With CreditWise, you can access your free TransUnion® credit report and VantageScore® 3.0 credit score without hurting your score. Plus, it’s free and available to everyone, whether or not you’re a Capital One cardholder.

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